Allow sub typing from bool to int in bounds computation
Allow sub typing from bool to int in bounds computation

jjdekker/libminizinc,jjdekker/libminizinc,tias/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc,jjdekker/libminizinc,jjdekker/libminizinc,tias/libminizinc